Implement Valve game directory detection check to prevent incorrect use of mod dlls

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Half-Life Updated changelog
 
+## Changes in V1.0.0 Release Candidate 004
+
+### Bug fixes
+
+* Disabled GCC optimization that prevents mod dlls from unloading after engine calls dlclose
+
+### Features
+
+* Mods made with this SDK will now shut down if they detect they are being run from a Valve game directory (e.g. by placing the dlls in `Half-Life/valve/cl_dlls` and `Half-Life/valve/dlls`). This is not supported and puts users at risk of being VAC banned. Run mods from their intended location only
+
 ## Changes in V1.0.0 Release Candidate 003
 
 ### Bug fixes

cl_dll/cdll_int.cpp

@@ -18,6 +18,8 @@
 // this implementation handles the linking of the engine to the DLL
 //
 
+#include <SDL2/SDL_messagebox.h>
+
 #include "hud.h"
 #include "cl_util.h"
 #include "netadr.h"
@@ -108,6 +110,28 @@ void DLLEXPORT HUD_PlayerMove(struct playermove_s* ppmove, int server)
 	PM_Move(ppmove, server);
 }
 
+static bool CL_InitClient()
+{
+	EV_HookEvents();
+	CL_LoadParticleMan();
+
+	if (!FileSystem_LoadFileSystem())
+	{
+		return false;
+	}
+
+	if (UTIL_IsValveGameDirectory())
+	{
+		SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Fatal Error",
+			"This mod has detected that it is being run from a Valve game directory which is not supported\n"
+			"Run this mod from its intended location\n\nThe game will now shut down", nullptr);
+		return false;
+	}
+
+	// get tracker interface, if any
+	return true;
+}
+
 int DLLEXPORT Initialize(cl_enginefunc_t* pEnginefuncs, int iVersion)
 {
 	gEngfuncs = *pEnginefuncs;
@@ -119,15 +143,15 @@ int DLLEXPORT Initialize(cl_enginefunc_t* pEnginefuncs, int iVersion)
 
 	memcpy(&gEngfuncs, pEnginefuncs, sizeof(cl_enginefunc_t));
 
-	EV_HookEvents();
-	CL_LoadParticleMan();
+	const bool result = CL_InitClient();
 
-	if (!FileSystem_LoadFileSystem())
+	if (!result)
 	{
+		gEngfuncs.Con_DPrintf("Error initializing client\n");
+		gEngfuncs.pfnClientCmd("quit\n");
 		return 0;
 	}
 
-	// get tracker interface, if any
 	return 1;
 }
 

dlls/game.cpp

@@ -454,6 +454,23 @@ cvar_t sk_player_leg3 = {"sk_player_leg3", "1"};
 
 // END Cvars for Skill Level settings
 
+static bool SV_InitServer()
+{
+	if (!FileSystem_LoadFileSystem())
+	{
+		return false;
+	}
+
+	if (UTIL_IsValveGameDirectory())
+	{
+		g_engfuncs.pfnServerPrint("This mod has detected that it is being run from a Valve game directory which is not supported\n"
+			"Run this mod from its intended location\n\nThe game will now shut down\n");
+		return false;
+	}
+
+	return true;
+}
+
 // Register your console variables here
 // This gets called one time when the game is initialied
 void GameDLLInit()
@@ -465,8 +482,9 @@ void GameDLLInit()
 	g_footsteps = CVAR_GET_POINTER("mp_footsteps");
 	g_psv_cheats = CVAR_GET_POINTER("sv_cheats");
 
-	if (!FileSystem_LoadFileSystem())
+	if (!SV_InitServer())
 	{
+		g_engfuncs.pfnServerPrint("Error initializing server\n");
 		//Shut the game down as soon as possible.
 		SERVER_COMMAND("quit\n");
 		return;

game_shared/filesystem_utils.cpp

@@ -53,6 +53,7 @@ static CSysModule* g_pFileSystemModule = nullptr;
 // The engine's filesystem doesn't provide functions to do this so we have to work around it.
 static std::string g_GameDirectory;
 static std::string g_ModDirectory;
+static std::string g_ModDirectoryName;
 
 static bool FileSystem_InitializeGameDirectory()
 {
@@ -97,18 +98,17 @@ static bool FileSystem_InitializeGameDirectory()
 
 	gameDirectory.shrink_to_fit();
 
-	std::string modDirectory;
-	modDirectory.resize(BufferSize);
+	g_ModDirectoryName.resize(BufferSize);
 
 #ifdef CLIENT_DLL
-	modDirectory = gEngfuncs.pfnGetGameDirectory();
+	g_ModDirectoryName = gEngfuncs.pfnGetGameDirectory();
 #else
-	g_engfuncs.pfnGetGameDir(modDirectory.data());
-	modDirectory.resize(std::strlen(modDirectory.c_str()));
+	g_engfuncs.pfnGetGameDir(g_ModDirectoryName.data());
+	g_ModDirectoryName.resize(std::strlen(g_ModDirectoryName.c_str()));
 #endif
 
 	g_GameDirectory = std::move(gameDirectory);
-	g_ModDirectory = g_GameDirectory + DefaultPathSeparatorChar + modDirectory;
+	g_ModDirectory = g_GameDirectory + DefaultPathSeparatorChar + g_ModDirectoryName;
 
 	return true;
 }
@@ -181,6 +181,11 @@ void FileSystem_FreeFileSystem()
 	}
 }
 
+const std::string& FileSystem_GetModDirectoryName()
+{
+	return g_ModDirectoryName;
+}
+
 void FileSystem_FixSlashes(std::string& fileName)
 {
 	std::replace(fileName.begin(), fileName.end(), AlternatePathSeparatorChar, DefaultPathSeparatorChar);
@@ -310,3 +315,30 @@ bool FileSystem_WriteTextToFile(const char* fileName, const char* text, const ch
 
 	return false;
 }
+
+constexpr const char* ValveGameDirectoryPrefixes[] =
+	{
+		"valve",
+		"gearbox",
+		"bshift",
+		"ricochet",
+		"dmc",
+		"cstrike",
+		"czero", // Also covers Deleted Scenes (czeror)
+		"dod",
+		"tfc"};
+
+bool UTIL_IsValveGameDirectory()
+{
+	const std::string& modDirectoryName = FileSystem_GetModDirectoryName();
+
+	for (const auto prefix : ValveGameDirectoryPrefixes)
+	{
+		if (strnicmp(modDirectoryName.c_str(), prefix, strlen(prefix)) == 0)
+		{
+			return true;
+		}
+	}
+
+	return false;
+}

game_shared/filesystem_utils.h

@@ -44,6 +44,11 @@ inline IFileSystem* g_pFileSystem = nullptr;
 bool FileSystem_LoadFileSystem();
 void FileSystem_FreeFileSystem();
 
+/**
+*	@brief Returns the mod directory name. Only valid to call after calling FileSystem_LoadFileSystem.
+*/
+const std::string& FileSystem_GetModDirectoryName();
+
 /**
 *	@brief Replaces occurrences of ::AlternatePathSeparatorChar with ::DefaultPathSeparatorChar.
 */
@@ -102,6 +107,12 @@ std::vector<std::byte> FileSystem_LoadFileIntoBuffer(const char* fileName, FileC
 */
 bool FileSystem_WriteTextToFile(const char* fileName, const char* text, const char* pathID = nullptr);
 
+/**
+*	@brief Returns @c true if the current game directory is that of a Valve game.
+*	Any directory whose name starts with that of a Valve game's directory name is considered to be one, matching Steam's behavior.
+*/
+bool UTIL_IsValveGameDirectory();
+
 /**
 *	@brief Helper class to automatically close the file handle associated with a file.
 */